GENETIC AND EPIGENETIC FACTORS IN TWIN PREGNANCIES: IMPACT ON MODERN DIAGNOSTICS AND PERINATAL OUTCOMES

Аннотация

Twin pregnancies, encompassing both monozygotic (MZ) and dizygotic (DZ) types, represent a unique model for studying the interplay between genetic and epigenetic factors due to shared or divergent intrauterine environments. This review synthesizes current evidence on how genetic predispositions and epigenetic modifications, such as DNA methylation and histone alterations, influence prenatal diagnostics and perinatal outcomes in twin gestations. Key epigenetic mechanisms, including hypomethylation of repetitive elements like LINE-1 and variations at polycomb group target genes, are implicated in discordances observed in MZ twins, particularly in conditions like twin-twin transfusion syndrome (TTTS). Modern diagnostic tools, including non-invasive prenatal testing (NIPT), chromosomal microarray analysis (CMA), and ultrasound-based nuchal translucency (NT) measurements, have enhanced detection rates of chromosomal abnormalities and structural anomalies, leading to improved risk stratification. Perinatal outcomes, such as preterm birth, intrauterine growth restriction (IUGR), and congenital heart diseases (CHD), are adversely affected by these factors, with MZ twins exhibiting higher risksdue to chorionicity-related complications. Data from multi-cohort studies indicatepersistent epigenetic signatures from early embryonic development, enriching regions near telomeres and centromeres, which correlate with long-term health disparities. This analysis, based on a comprehensive literature review of over 50 studies from 2010 to 2024, highlights the need for integrated genetic-epigenetic screening to optimize perinatal care. Implications include personalized interventions like fetal surgery for TTTS and advanced epigenetic profiling to mitigate adverse outcomes, potentially reducing neonatal morbidity by up to 20-30% in high-risk cases. KEYWORDS: Twin pregnancies; Monozygotic twins; Dizygotic twins; Epigenetics; DNA methylation; Prenatal diagnostics; Perinatal outcomes; Twin-twin transfusion syndrome; Chromosomalmicroarray analysis; Nuchal translucency